Comparative study of physical properties of enzymatic in situ hydrogels based on bovine Achilles tendon collagen and rat tail collagen

Collagen type I, as a biomimetic material, has wide applications in tissue engineering and drug delivery. Still, there are limited comparative studies between different methods of constructing scaffolds or carriers based on different collagen sources. In situ gel through the enzymatic method in the presence of horseradish peroxidase (HRP) as the enzyme and hydrogen peroxide (H₂O₂) is one of the appealing noninvasive methods due to rapid gelation in a mild condition. In this study, a comparison was made between two in situ gels constructed by HRP/ H₂O₂ method based on bovine Achilles tendon collagen (Bovine Coll) and rat tail tendon collagen (Rat Coll). After collagen extractions, tyramine was incorporated on the collagen backbones. The extent of modification was 39.95 μg/mg (tyramine per collagen) and 26.94 μg/mg (tyramine per collagen) for Bovine Coll and Rat Coll, respectively. The evaluations of morphology, rheology, and degradation were performed to compare the hydrogels formed. Bovine Coll based hydrogel (BC-hyd) showed smaller average pore size, higher mechanical strength, and longer degradation time in comparison to Rat Coll based hydrogel (RT-hyd).